This grant aims to develop better methods of characterizing the intrauterine clinical condition of fetuses with life-threatening arrhythmias, acquired heart failure, and structural congenital heart disease. We hypothesize that direct simultaneous comparison of fetal electrocardiographic fECG and magnetocardiographic (fMCG) recordings in conjunction with Echocardiography and Doppler (echo/Doppler), will enhance current echo/Doppler capabilities of recognizing the fetus at risk of life-threatening cardiac complications. Electrophysiological and mechanical interactions in the fetus are largely unstudied. It is accepted that electromechanical dysfunction contributes to cardiac remodeling, cardiac failure, and adverse clinical outcomes in adult arrhythmia and cardiomyopathy patients. Using fetal cardiogram monitoring in conjunction with echo/Doppler, we propose to record synchronized and simultaneous measurements in 5-10 healthy pregnant women to prove that echo/Doppler and fMCG are compatible techniques. This preliminary work is a prerequisite to validation of echocardiographic quantitative techniques, which have not been validated with the fetal cardiac signal. In Phase I, we intend to demonstrate the ability to take SQUID magnetometry and ultrasound measurements simultaneously. We will then determine what, if any, modifications need to be made to either the SQUID or ultrasound electronics to design a commercial prototype combined instrument capable of being used for fetal cardiography in a clinical setting.